Oldsmobile 1995 88 Owner's Manual page 93

Once the compass is calibrated, it does not need to be
recalibrated for any zone as long as the mirror is left in
your vehicle and the vehicle remains in the same
geographical zone.
To calibrate the compass:
1. Set the switch on the mirror control to C M .
2. Turn vehicle ignition switch on. The letter C should
be displayed in the mirror compass window. If not,
hold in the calibration switch for more than 10
seconds, and the letter C will appear. To hold in the
calibration switch, insert a paper clip into the small
hole on the bottom of the mirror housing. The
display will show a number first, but keep holding
until the letter C appears.
3. Quick Calibration: Drive the vehicle in a 360-degree
circle at less than 5 mph (8
M)
until the display
reads a compass direction. Normal Calibration:
Drive the vehicle on your everyday routine, and the
compass will eventually calibrate.
Compass variance is the difference between magnetic
north and geographic north. In some areas the difference
between the two can be great enough to cause false
compass readings. If this happens, follow these
instructions to set the variance for your particular
location:
1. Locate your location on the zone map. Note your
zone number.
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